1. Field of the Invention
With reference to the classification of art as established in the United States Patent Office the present invention pertains to art as found in the general Class entitled, "Material or Article Handling" (Class 214) and the subclass entitled, "transfer devices -- reciprocating type" (subclass 1BB). Also of note is the art in the general Class entitled, "Machine Elements and Mechanisms" (Class 74) and the subclass entitled, "automatic operation or control" (subclass 2).
2. Description of the Prior Art
Spring-type ejector pins and levers used with punch presses and mounted dies are well known and are often designed and furnished as a basic component of dies used with and in punch press operations. Hold-downs and step-wise advancing mechanisms are also well known in the punch press industry. In recent years for difficult high speed removal of a product there has been used a controlled jet of air providing an ejector means to blow formed, sheared, or compound-formed and sheared members from dies and the like. These jets of air in combination with the removal action of the piece parts are often noisy and in certain circumstances approach, if they do not exceed, the permissible tolerant noise levels now established by Federal law.
The present invention provides apparatus that is relatively silent during ejecting action and during the extending of the tension springs, as well as virtually silent or completely silent during all other phases of operation. The force required to extend the springs is small and is exerted during that part of the press ram movement which occurs during a portion of the travel stroke not immediately used for forming or cutting of the product part. The present invention permits the loading and ejecting cycle to be adjusted to suit the operating cycle. In particular, when used with a forming die the trigger is adjusted so that the ejector release motion occurs only after the die has opened a selected amount. It is to be noted that simple mechanical actions and components are employed so that the service life expectancy of the ejector mechanism and its components is in the millions of cycles. Its adaptability to punch press and similar operations with a minimum of design consideration is also a great assistance to the designer. An ejector mechanism is provided which does not require pressurized air to remove items from a transport means.
The ejector mechanism utilizes a spring-biased plunger which is energized by a movement of the associated apparatus. A coupled pair of actuator levers is moved to load springs connected to the ejector plunger and the springs and plunger are maintained in the desired loaded or cocked condition until a trigger is actuated to release the ejector plunger which is moved a determined distance under the influence of the released springs. The releasing of the ejector plunger usually occurs in the up stroke portion of the press cycle and after forming and/or cutting. The release of the spring stored energy causes the ejector plunger to move a desired distance and engage and dislodge that piece which is to be ejected.